Apparatus for air driving of strip screws



APPARATUS FOR AIR DRIVING OF STRIP SCREWS Filed Oct. 5. 1966 Sheet 7 l of 4 INVENTOR HERBERT C. B RAUCHLA BY w , ATTORNEYS Jan. 14, 1969 H. c. BRAUCHLA APPARATUS FOR AIR DRIVING OF STRIP SCREWS Sheet Filed Oct. 5, 1966 ATTORNEYS H. C. BRAUCHLA APPARATUS FOR AIR DRIVING OF STRIP SCREWS Jan. 14, 1969 Filed Oct. 5, 1966 Sheet k-IIZ ATTORNEYS Jan. 14, 1969 H. C. BRAUCHLA APPARATUS FOR AIR DRIVING OF STRIP SCREWS Sheet Filed Oct. 5, 1966 INVENTOR HERBERT c. BRAUCHLA Ms W ATTORNEYS United States Patent 3,421,557 APPARATUS FOR AIR DRIVING OF STRIP SCREWS Herbert C. Erauchla, Fremont, Ohio, assignor of one-half to J. D. Guernsey, Fostoria, Ohio Filed Oct. 3, 1966, Ser. No. 583,775 US. Cl. 14432 Claims Int. Cl. B251) 23/00 The present invention relates to driving of strip screws of the type described in applicants Patent No. 3,284,125, entitled, Method of Forming Screw Strip (Ser. No. 530,132, filed Feb. 25, 1966), particularly a method and gun apparatus for driving strip screws by an air motor.

The present invention is an improvement upon the invention described in Patent No. 3,258,042 and assigned to applicant herein. In the patent, the strip screw is rotated, then longitudinally advanced by means of a pair of pivoted threaded cams radially extensible through the top and bottom of a rotatable driving barrel so as to engage and lock upon threads of the screw upon axial advancement of the locking sleeve. According to the present invention, the axial advancement of the screw strip is effected by the locking sleeve having radially inwardly extending jaws which engage the rear head of the individual screws to be driven. This engaging of the rear of the screw head enables a positive advance of the screw strip without attempting to engage the screw threads for advancement. Separately, one or more pairs of radially inwardly extending thread-engaging jaws are employed to engage the screw threads so as to lock the screw strip against reverse longitudinal movement when the locking sleeve is reversely longitudinally moved for re-engaging a succeeding screw head in the strip screw.

As a result, there is provided a more positive advancing of the strip screw to be driven and a more effective locking of the strip against reverse longitudinal movement. Also, there is provided a positive action for advancing the leading screw shank from the end of the barrel without continuing to rotate the barrel.

Accordingly, it is an object of invention to provide an improved method for air driving of strip screws.

Another object of invention is to provide an improved gun for the air driving of strip screws.

Yet, additional objects will become apparent from the ensuing specification and attached drawings wherein:

FIG. 1 is a perspective view of an air driven strip screw gun, showing the strip screw 26 extending into the feeding end of the gun and an individual screw shank threaded portion 30 protruding from the discharge end of the gun;

FIG. 2 is a vertical section thereof, showing the advancing sleeve locking jaws 84 and 86 stripping over the individual screw head in a reverse longitudinal movement;

FIG. 3 is a fragmentary perspective of the discharge end of the rotating barrel, showing the advancing sleeve locking jaws 84 and S6 in an attitude of being urged against the rear of the individual screw heads 28 while commencing to forwardly advance the strip screw so as to force the lead screw shank outwardly of the rotating barrel muzzle;

FIG. 4 is a front elevation of the gun;

FIG. 5 is a bottom plan; and

FIG. 6 is an enlarged perspective of a screw strip of the type which can be driven according to the present invention.

In FIG. 1 screw strip driving gun 10 is illustrated as comprised of mid-portion housing 12 integrally arranged with a downwardly extending handle 14 and having attached thereto by means of alien head screws or the like forward housing 16 and rearward housing 18. A depressible trigger 22 is secured to handle 14, as will be hereinafter described. A rotatable strip screw driving bar- "ice rel 24 having an interior bore 122 configured complementally with the individual screw strip heads is mounted within the gun and at its feeding end has a cover 26 which may be thrededly supported in one end of rear housing 18.

As illustrated in FIGS. 1 and 6, the individual strip screw 26 is comprised of individual screws having heads 28, threads 30 and reduced diameter tip 32.

Rotatable barrel 24 is mounted within housing midportion 12 by means of rear ball bearing assembly 34 and lock washer 38, as well as forward ball bearing assembly 36, having lock washer 40. A collar 42 having horizontally disposed miter gear 44 is supported about barrel 24 so as to engage vertical miter gear 46 seated upon conventional air motor 48 having shaft 50 extending through its bottom into the threaded bottom cap 54. Air motor 48 may be secured in handle 42 by means of O-ring 52.

Air pressure derived from any suitable source may be fed into air intake port 58, then proceeding via reduced diameter valve seat 62 into motor and exhaust channel 56 and advancing sleeve channel 57, thence into air chamber 74. Air is exhausted from motor 48 by means of exhaust channel 60, as illustrated in FIGS. 2 and 5. Trigger 22 is supported upon guide stud 72 threadedly seated in handle 14 and has actuating pin 66 engaging the reduced diameter valve 62, in turn seated upon depressible base 71 which is mounted upon coil springs 68 by means of O- ring 7. Advancing sleeve 81 is supported about rotatable barrel 24 within forward housing 16 and has attached threaded adjusting collar 78. An O-ring sealing element 76 is secured to collar 78 by means of lock washer 80 or the like. A compression spring 82 encircles advancing sleeve 81 and at its forward end abuts inner shoulder 102 in housing 16. By longitudinally advancing or retreating collar 78 upon sleeve 81 the compression of spring 82 is varied to accommodate strip screws having shanks of varying length.

At the forward end of advancing sleeve 81 are mounted radially inwardly extending pivoted cams 84 and 86 inwardly urged by means of leaf springs 90 and 92 secured to the barrel by set screws or the like. Cams 84 and 86, as illustrated in FIG. 3, have perpendicular advancing surfaces 98 and 100 which engage the rear of the screw head 28 and urge the screw head axially forward, as air is released into air chamber 74, so as to compress spring 82 and urge the sleeve 81 forwardly. This action occurs immediately as trigger 22 is depressed. Thus, the lead screw shank is advanced outwardly of the discharge end of rotatlng barrel even though the trigger may be released and rotating of the barrel has ceased.

In FIG. 2 the reverse axial movement of advancing sleeve 81 is shown wherein jaws 84 and 86 strip reversely over the heads 28 of an individual screw while the screw strip 26 is locked against reverse longitudinal movement by a pair of identical forward radially extending cams 103 urged inwardly by leaf springs 104 secured in set screws 108 and extending inwardly of apertures 110 in the forward end of barrel 24. A similar pair 114 of thread-engaging cams is positioned at the feeding or rear end of barrel 24 and is urged inwardly through barrel 24 apertures by means of leaf springs 116 secured in set springs 118. An increased diameter bore portion 112 may be supported at the screw driving end of barrel 24, as illustrated in FIG. 2 so that driving torque is applied to the heads of all strip screws with the exception of the lead screw which is sheared from the reduced diameter tip 32 of the screw next to be driven.

As will be apparent, driving of screws according to the present method virtually eliminates operator error. The torque to be applied to individual screws can be adjusted by varying the diameter of the leading tip portion 32 or by varying the air pressure applied to the air motor to drive the barrel. Also, as will be apparent, it is not necessary that the strip screws be advanced with their reduced diameter tips forwardly disposed. Rather, if desired, the entire strip screw may be reversed so that the individual heads of the screws are presented firstly out of the discharge end of the barrel. This mode of driving can be used when the individual screws or bolts are to be welded or otherwise secured to a supporting surface according to the conventional methods.

The interior bore 122 of the rotating barrel 24 can be variously configured to accommodate any type of strip screw head. Manifestly, various changes in the driving gun structure can be imparted without departing from the spirit and scope of invention, as defined in the subjoined claims.

What is claimed is:

1. A strip screw driving gun of the type utilizing air power and having a housing and handle attached thereto, comprising:

(A) a rotatable barrel extending through said housing and having an inner bore complementally configured with the heads of individual screws in the strip screw being driven, said bore having a screw driving end and a strip screw receiving muzzle;

(B) air driving means supported in said handle and engaging said rotatable barrel;

(C) a locking sleeve supported about the forward end of said barrel and communicable with said air driving means for axial advancement, said locking sleeve having at its forward ends a pair of spring urged screw head engaging jaws radially inwardly extending into the bore of said barrel so as to engage the rear of a screw head upon advancement of said sleeve, said locking sleeve being reversely spring-urged to strip over said screw strip heads upon release of said air driving means;

(D) trigger means pivoted in said housing so as to regulate flow of air to both said air motor and said locking sleeve; and

(E) at least one pair of opposed, thread-engaging jaws radially inwardly urged through said barrel to engage said screw threads to prevent reverse longitudinal movement of said strip upon release of said driving means.

2. A strip screw driving gun as in claim 1, said trigger being positioned to admit air to said locking sleeve simultaneously with driving of said barrel so as to advance said screw strip upon rotation of said barrel.

3. A strip screw driving gun as in claim 1, including pairs of opposed, thread-engaging jaws longitudinally spaced so as to engage said threads on either side of screw head engaging jaws in said locking sleeve.

4. A strip screw driving gun as in claim 3, said locking sleeve including longitudinal adjusting means varying reverse longitudinal movement of said sleeve for screws having shanks of diiferent length.

5. A screw strip driving gun as in claim 4, said air driving means communicating anteriorly with said locking sleeve and posteriorly with said rotatable barrel so as to longitudinally advance said screw strip and its lead screw prior to rotation.

References Cited UNITED STATES PATENTS 3,052,271 9/1962 Muenchinger -a 14432 3,258,042 6/1966 Ruminsky 144-32 3,356,112 12/1967 'Ruminsky et al. 144-32 DONALD R. SCHRAN, Primary Examiner. 

1. A STRIP SCREW DRIVING GUN OF TYPE UTILIZING AIR POWER AND HAVING A HOUSING AND HANDLE ATTACHED THERETO, COMPRISING: (A) A ROTATABLE BARREL EXTENDING THROUGH SAID HOUSING AND HAVING AN INNER BORE COMPLEMENTALLY CONFIGURED WITH THE HEADS OF INDIVIDUAL SCREWS IN THE STRIP SCREW BEING DRIVEN, SAID BORE HAVING A SCREW DRIVING END AND A STRIP SCREW RECEIVING MUZZLE; (B) AIR DRIVING MEANS SUPPORTED IN SAID HANDLE AND ENGAGING SAID ROTATABLE BARREL; (C) A LOCKING SLEEVE SUPPORTED ABOUT THE FORWARD END OF SAID BARREL AND COMMUNICABLE WITH SAID AIR DRIVING MEANS FOR AXIAL ADVANCEMENT, SAID LOCKING SLEEVE HAVING AT ITS FORWARD ENDS A PAIR OF SPRING URGED SCREW HEAD ENGAGING JAWS RADIALLY INWARDLY EXTENDING INTO THE BORE OF SAID BARREL SO AS TO ENGAGE THE REAR OF A SCREW HEAD ADVANCEMENT OF SAID SLEEVE SAID LOCKING SLEEVE BEING REVERSELY SPRING-URGED TO STRIP OVER SAID SCREW STRIP HEADS UPON RELEASE OF SAID AIR DRIVING MEANS; (D) TRIGGER MEANS PIVOTED IN SAID HOUSING SO AS TO REGULATE FLOW OF AIR TO BOTH SAID AIR MOTOR AND SAID LOCKING SLEEVE; AND (E) AT LEAST ONE PAIR OF OPPOSED, THREAD-ENGAGING JAWS RADIALLY INWARDLY URGED SAID BARREL TO ENGAGE SAID SCREW THREAD TO PREVENT REVERSE LONGITUDINAL MOVEMENT OF SAID STRIP UPON RELEASE OF SAID DRIVING MEANS. 